Apparatus for signaling between two points on a railroad train



1,885,909 APPARATUS FOR SIGNALING BETWEEN TWO POINTS ON A RAILROAD TRAIN R. GlLSON Nov. 1, 1932.

Filed March 24, 1931 Patented Nov. 1, 1932 ROBERT IVE. GILSO'N, PITTSBURGH, PENNSYLVANIA, ASSIGNOR 1'0 THE UNION 82; SIGHAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A COBI'ORATION OF PENNSYL- VANIA arrnnarns ron srennmne n nrwnnn ewaeems on n nalnaoan TRAIN Application filed March 24, 1931. set-m1 in. 524,824.

My invention'relatesto trackway apparatus for use in connection with electrical systems of signaling between two polnts on a railroad train through the track rails and the ground. c

One form of train signaling system with which my invention may be used, is disclosed and claimed in an application for Letters Patent of the United States filed by L. O.

' Grondahl on May .6, 1930, Serial No. 450,135, 7 for apparatus for signaling between two points on a railroad train. When train signaling systems of this type are used on a railway having the usual insulated track sections provided with track circuits, I have found that it is advantageous to electrically connect the rails of an occupied section with the rails of the section next in the rear, and one feature of my present invention is the provision of means for doing this without interfering with the operation of the track circuits.

I will describe one form. of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the track rails of a railway track along which traflic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 2 to form track sections A-B, B-C, etc, and each track section is provided with the usual track circuit comprising a source of current 3, such as battery, and a track relay D. These track relays may be used for the control of wayside signals or other traffic governing devices, but these signals or devices form no part of my present invention, and, consequently, they are not illustrated in the drawing.

An impedance 4 is connected across the track rails at each end of each section. As here shown, these impedances are non-inductive resistances, but other forms of impedance may be used to meet the requirements of existing conditions. The middle points and scope of my invention.

of the two impedances 4 adjacent the junction of each two track, sections are electrically connected througha back contact 5 of the track relay D. for the forward of such sections, so that this connection is closed when and only when such forward section is occupied by a train. For ordinary d1rectcurrent track circuits, each resistance t may be of approximately 10 ohms, so that when the connection between two adjacent resistances is closed, the resistance of the path from the rails of one section to the rails of the other section is approximately 5 ohms. Resista'nces of this value will not materially interfere with the normal operation of the track cir- Assuming now that a train T occupies'section B',C, and that the rear'end. of this train has passed into the section, it will be observed that in the absence of apparatus emrent could flow from therails of section B-C to" ground, because of the high resistance between the rails of this section'in the rear of the train andthe ground. With apparatus embodying my invention, however the train signaling current willfiow through the resistances 4: and the back contact 5 of relay D 1 immediately in the rearof the train, and will thus reach the rails of section A-B from return to the'front end of the train T. The

resistance of ,5 ohms presented to thiscurrent by the apparatus at point-B will not be sufficient to interfere with the proper operation of the train signaling system. i Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications maybe made therein withinthe scope of the appended claims without departing from the spirit Having thus described my invention, what Iclaimis: I, v 1. Trackway apparatus for use in connection with an electrical system of signaling.

between two points on a train through the track rails and the ground, comprising, in combination with the usual insulated track sections each provided with a track relay, an impedance connected across the rails at each end of each section, and a connection between each two adjacent impedances including a back contact of the adjacent track relay.

2. Trackway apparatus for use in connection with an electrical system of signaling between two points on a train through the track rails and the ground, comprising, in combination with the usual insulated track sections each provided with a track relay, an impedance connected across the rails at each end of each section, and a connection between the two impedances adjacent the junction of each two track sections which connection is closed when and only when the track relay for the forward of such sections is open. a

3. Trackway apparatus for use in connection with an'electrical system of signaling between two points on a train through the track rails and the ground, comprising, in combinat1on with the usual lnsulated track sectlons each provided with a track relay, a resistance connected across the rails at each endof each section, andmeans for electrically connecting a the two resistances adjacent the junction of each two track sections when and only when tion-with an electrical system of signaling between two points on a train'through the track rails and the ground, comprising, in

combination with the usual insulated track sections each provided with a track relay, a

, resistanceconnected across the rails at each end of each section, and a connection between the middle points of the two resistances adjacent the junction of each twotrack sections including a back contact of the track relay for one of such sections,

5. Trackway apparatus for use in connection with an electrical systemof signaling between two points on'a train through the track rails and the ground, comprising in combination with the usual insulated track sections each provided with a normally closed tracy relay, means for electrically connecting the rails of each two adjoining sections when and only when the track relay'for one of such sections is open.

6. Trackway apparatus for use in connection with an electrical system of signaling tween two points on a train through the tr ck rails and the ground, comprising, in

of each two adjoining sections including a 7. Trackway apparatus for use in connection with an electrical system of signaling between two points on a train through the track rails and the ground, comprising, in combination with the usual insulated track sections, means for electrically conecting the rails of two adjoining sections when and only when at least one of such sections is occupied by a train.

'8. Trackway apparatus for use in connection with an electrical system of signaling between two points on a train through the track rails and the ground, comprising, in combination with the usual insulated track sections, means for electrically connecting the rails of two adjoining sections when and only when the forward of such sections is occupied by a train.

"In testimony whereof I aflix my signature.

ROBERT M. GILSON.

combination with the usualinsulated track vsections each provided with a normally closed track relay, a connection between .the rails 

